Apparatus for graining explosive powder.



P. I. DU PUNT. v APPARATUS POP. GRAINING BXPLOSIVP POWDER.

APPLICATION I'LBD JUNE 12, 1912.

Patented Nov. 3, 1914.

2 SHEETS- SHEET 1.

IE. I. DU PONT.

APPARATUS POP. GRAINING BXPLOSIVB POWDER.

APPLIOATIQN FILED JUNE 12., 1912.

Patented N0v.3,1914' 2 SHEETS-SHEET 2.

FRANCIS I. DU PONT, OF WILMINGTON, DELAWARE.

rAIPPAR.A'JIUS FOR GRAINING EXPLOSIVE POWDER.

Specification of Letters Patent.

Patented N ov. 3, 1914.

Application led .T une 12, 1912. Serial No. 703,108.

T all whom t may concern Be it known that LFRANors L. DU PONT. a citizen of the United States, residing at ll'vilmington, county of New Castle, and State of Delaware, have invented a new and useful Improvement in Apparatus for Graining Explosive Powder, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, which form a part of this specification. Y

The object of my invention is to provide u Corning mill for reducing powder cakes to grain, operatinor in such a way that in the event of firing there will be little, if any, risk of loss of life or serious bodily injury and no destruction of the heavier and more expensive machinery.

A. further object of the invention is to minimize the expense of construction.

In my invention the mill is so constructed that only an exceedingly small quantity of explosive will be acted upon at a given time, so that in the event Vof firing, the field of danger will be quite limited, thus minimizing the danger to the attendant and avoiding damage to the heavier and more expensive machinery actuating and coperating with the graining mechanism and the immediately adjacent distributing means. The construction also avoids the employment of a multiplicity of graining rolls and the use of shakers. the mechanism therefore being of relatively inexpensive construction.

In the drawings, which illustrate a preferred form of apparatus embodying my invention, Figure l is a side elevation, mainly diagrammatic, of my improved Corning mill. Fig. 2 is an enlarged plan view of a part of the. layout shown in Fig. 1. Figs. 3 and i are cross sections on the line 3.-3 and 4-4 of Fig. 2. Fig. 5 is a detail elevational view of a portion of the convey'er troughs and ropes. Fig. 6 is a vertical' cross section through same.

The press cake is fed from the feed apron u. to the cutting rolls b, which are arranged one above the other. Thence the pieces of cut press cakes pass down they chute c to a metal conveyer trough d. The trough d is U-sh'aped, and the end thereof under and adjacent to the chute is imperforate. The remainder of the trough has holes e in its bottom, such holes being of suiciently large size to allow the pieces of cut press cake to escape therethroug Beneath-the perforated part of the trough cl is a pair of graining rolls g. These rolls are of comparatively great length and large diameter and are caused to rotate at a very slow speed. The space between the rolls is directly under the longitudinal center of the trough d.

Traveling through .the trough, d along its bottom and in the direction of the arrow (to the right, Fig. l), is conveyer rope f. The purpose of the rope is to convey the pieces of cut press cake to the perforated portion of the trough d and to distribute the cut cake along the graining rolls g and to maintain' the spacebetween the trough and the rolls full of cut cake until within a safely shortv diltance of the far ends of the trough and ro s. v s The rolls g are mounted in bearings z. which are adjustable by means of threaded shafts and hand-wheels z'. f

Beneath the mouth of the rolls g and extending for some distance to the left thereof is another trough 7c which receives the grain into which the pieces of cut press cake are cracked by the rolls. Traveling through the trough lc and in the direction of the arrow (to the left, Fig. l) is a conveyer rope m, by means of which the grain is carried out of the trough and beyond it to the point. of delivery, as will be hereinafter described. The trough k has holes Z in its bottom of only suicient size to allow the escape of dust into the imperforate trough n., which is located immediately beneath the trough 7c.' Traveling through the trough n and in the direction of the arrow is a conveyer rope o, bv means of which the dust is carried out of the trough and beyond' it to the point of delivery, as will be hereinafter described.

At a substantial distance beyond the troughs d, and n, and the graining rolls g is a barricade 1'. Three tubes d', lo', and n extend from the left-hand ends of the troughs d, lr: and n through the barricade beyond the delivery points for the grain and dust. A fourth tube 72 is located above the other three tubes and troughs. The oo nveyer ropes f, m and o are preferably different sections or reaches of a single endless rope, which passes through the tubes al', 7c' and n and also through the tube p, the ar- Mens?? rangement that I have adopted being as follows: Starting from the trough d at the point of delivery thereto of the cutpieces of press cake, the rope extends to the right through trough d. thence around an idler pulley 10, thence through trough 7c, thence through tube lv', thence around an idler pulley 11, thence through tube p, thence around a driving pulley 12, thence under an idler pulley 13, thence through trough n, thence through tube a', thence around an idler pulley 14 and thencethrough ,tube CZ back to trough d. The rope f-Jm/-o is protected by other tubes or covers at all points throughout its travel including the parts of the pulley peripheries with which the rope engages, so .that no part of the rope is expos Beyond the barricade 1' and between it and the pulleys 11 and 14, the tubes 1c and n are perforated lengthwise to communicate with hoppers s and t arranged respectively over cars u and o, to which the grain conveyed from trough k and the dust conveyed from trough n may be respectively delivered.

At the right hand end of trough d is arranged a passage fw leading to the trough la, the purpose of which is, in the event of overcrowding the mechanism, to carry the surplus uncrushed pieces of cut cake directly to the trough 7c. In the normal working of the mill, no cut pieces will be carried beyond the extreme end of the trough d, but if, under abnormal conditions, this happens, the only effect will be that the grain conveyed tothe car u will contain some large pieces which would go through the glazing milland be removed in the packing house. In this way it is impossible for the mechanism to become clogged.

The conveyer rope and the graining rolls may be driven by any suitable means. I have shown a driving pulley 20, which may be belted topa main driving shaft (not shown), and reduction gearing comprising a sha 21 geared to the pulley shaft, a shaft 22 geared to shaft 21, and shafts 23 and 24 both geared to shaft 22; the shafts 23 and 24 gearing with the respective graining roll shafts. The shaft 21 is also geared to the shaft 25, which carries the driving pulley-12.

The operation of the mill will be understood from the preceding description.

The press cakes are cut into pieces by the cutting rolls b and the cut pieces pass to the upper trough d, in which they are conveyed by the rope and distributed through the oriced part of the trough, from which they pass to the graining rolls g. The rolls turn very slowly, thus exerting an effect upon the cut pieces analogous to that produced by a vise, and hence avoiding any substantial production of flying dust or any pulverizing action. The large diameters of the rolls enable the cut pieces to be crushed down to grain size in a single operation. The grain, as well as the fine particles or any slight proportion of dust that may be produced, drops into the intermediate trough 1, whence such fine particles or dust pass to the lower trough The ropes passing through the troughs c and n carry the grain and dust beyond the barricade r to the receptacles provided for them.

The above construction minimizes pulverization and avoids flying dust. Instead of a multiplicity of graining rolls there is but a single roll and no shakers. The amount` of powder in the mill at any one time is exceedingly small and is distributed in a.

long train. Owing particularly to the last mentioned feature the powder in any part of the mill couldbe fired Without destructive effects and without burning the attendant. In case of firing the main heavyparts of the machinery would sustain -no damage and there would be necessity only for some repairs. Finally, the simplification of the mechanism renders the construction comparatively inex ensive.

Having now ully described my invention, whatI claim and desire to protect by Letters Patent is:

1. In a Corning mill, the combination with a pair of elongated graining rolls, of means to carry pieces to be reduced to grain longitudinally of the rolls and ldistribute them 'along the rolls, and means to receive the grain from the rolls and transfer it to a distant point.

2. In a corning mill, the combination with a plurality of troughs, of a pair of graining rolls between two of the troughs, means movable longitudinally of the rolls to distribute pieces of powder calze along one trough, and means permitting said pieces to pass from the last named trough through the rolls to the other trough.

3. Ina Corning mill, the combinationv with avpair of elongated graining rolls, of means to carry pieces to be reduced to grain longitudinally of the rolls and distribute them along the rolls, and means to carrv the grain produced by the rolls longitudinally thereof and transfer it to a distant point.

4. In a corning mill, the combination with an orificed trough adapted to receive the pieces to be reduced to grain, of a conveying and distributing device movable longitudinally therein, a pair of graining rolls to receive the cut pieces from said trough, and means to receive the grain from the rolls and transfer it to a distant point.

5. In a Corning mill, the combination with an orificed trough adapted to receive the pieces to be reduced to grain, of a conveying 'and distributing device movable longitudinally therein, a second trough beneath the l first trough, a pair of graining rolls arranged lopgitudinally of and between the two troughs, and a conveying device movable longitudinally in the second trough.

6. In a Corning mill, the combination with a pair of elongated graining rolls, of means to carry pieces to be reduced to grain longitudinally of the rolls and distribute them along the rolls, and means to separate the grain and liner particles emerging from the rolls and separately carry them longitudinally of the rolls toward a distant point.

7. In a Corning mill, the combination with three troughs, of a pair of graining rolls between the first and second trough, means to distribute pieces of powder cake along one trough and permit them to pass therefrom to the rolls, and means to permit fine particles to pass from the second trough to the third trough.

8. In a Corning mill, the combination with three troughs, of a pair of grainingrolls between the' first and second trough, means to distribute pieces'of powder cake along one trough and permit them to pass therefrom to the rolls, means to permit fine particles to pass from the second trough to the third trough. and means respectively in the second and third troughs to transfer the grain and fine particles therefrom to a distant point.r

9. In a co'rning mill, the combination with an orificed trough adapted tto receive the pieces to be reduced to grains, of a conveying and distributing device movable longitudinally therein, a second oriliced trough beneath the first trough, a pair of graining rolls arranged longitudinally of and between said troughs, a third trough beneath the second trough, and conveying devices movable longitudinally in the second and third troughs.

10. lIn a Corning mill, the combination with cutting rolls to reduce the press cake to cut pieces. a trough, means to convey the cut pieces from the cutting rolls to the trough, a distributing device in the trough, a pair of graining rolls beneath the trough, there being holes in the trough to permitthe out pieces to pass therefrom to the rolls, and means to receive the `grain from theA rolls and transfer it to a distant point.

11. In a corning mill, the combination with cutting rolls to reduce the press cake to cut pieces, a trough, means to convey the cut pieces from the cutting rolls to the trough, a distributing device in the trough, a pair of graining rolls beneath the trough, there being holes in the trough to permit the cut pieces to pass therefrom to the rolls, a second orifced trough to receive the grain and finer particles from the rolls, a third trough underneath the second trough to re-,

ceive the liner particles passing with the,

grain to the second trough, and traveling conveyer ropes in Vthe second and third troughs to remove the grain and finer particles therefrom.

12. In a Corning mill, the combination with a trough imperforate at one part thereof and orificed beyond said part, means to introduce the pieces to be grained into the imperforate part thereof, a conveying and distributing rope movable longitudinally therein, to convey the pieces to and distribute them along the oriiced part of the trough, a pair of graining rolls arranged un derneath the oriliced part of the trough and forming between and above them and beneath the trough an elongated pocketto receive the pieces to be grained, and means underneath the rollers to receive and remove the grain.

13. In a corningmill, the combination with a trough imperforate at one part there of and oriced beyond said part, means to introduce the pieces to be grained into the imperforate part thereof, a conveying and distributing rope movablel longitudinally therein, convey the pieces to and distribute them along the orificed part of the trough, a

pair of graining rolls arranged underneath the oriiced part of the trough and forming i between and above them and beneath' the trough an elongated pocket to receive the pieces to be grained, a second oriiced trough underneath the first trough to receive the grain from the rolls, a third trough underneath the second trough to receive the liner ,graining rolls between two of the troughs,

means permitting pieces of powder cake to be reduced to grain to pass from one trough through the rolls to another trough, a tube connecting with the last named trough, a

distributing device in the trough from whichthe pieces pass to the rolls, and a conveying device in the said receiving trough andtube to remove the grain and transfer it through the tube to a distant point.

15. In a co'rning mill, the combination with three troughs superposed one above the other, of a pair of graining rolls between the upper trough and the intermediate trough, means permitting pieces of powder cake to pass from the upper trough through the rolls to the intermediate trough, means permitting inerparticles to pass from the intermediate trough to the lower trough, tubes connecting with the intermediate and lower troughs, a distributing device in the upper trough, a conveying device in the intermediate trough and its connecting tube, and a conveying device in the lower trough and its connecting tube.

16. In a corning mill, the combination with a plurality of troughs superposed one fies above the other, a. pair of grainin rolls between two of the troughs, an en ess conveyer different reaches of which extend through the several troughs, and means to rotate the rolls and drive the conveyer.

17. In a cornin -mill the combination with a pair of graming rolls, of a trough ada ted to receive ieces to be grained and disc iarge them tot e rolls, a second trou h adapted to receive the grain from the rol s, a third trough'adapted to receive fine articles from the second trou h, an endless conveyer diierent reaches o which extend through the several troughs, and means to rotate the rolls and drive the conveyer.

18. In a corning mill, the combination with a pair of graming rolls, of a trough ada ited to receive ieces to be grained and disc large them to t ie rolls, a second trou h adapted to receive the grain from the rol s, n third trough adapted to receive fine particles from the second trough, tubes connecting respectively with the second and third troughs, an endless conveyer one reach of which extends throu h the first trough, and two other reaches o which extend res ectively through the other troughs and t eir rcssective tubes and means to rotate the rol s and drive the conve er.

19. In a Corning mi the combination with a pair of graining rolls, of a trough ada ted to receive ieces to be grained, and disc arge them to t e rolls, a second trough adapted to receive the grain from the rolls, a third trough adapted toreceive fine particles from the second trough, tubes connecting respectively with the three troughs, an endless'conveyer comprising four reaches, three of which extend respectively through the several troughs and their connecting tubes,` and means to rotate the rolls and drive the conveyer.

20. In a cornin mill the combination with a, pair of graining rolls, of a trough ada ted to receive ieces to be grained and disc ar e them to t e rolls, a second trough adapte to receive the grain from the rolls, a third trough adapted to receive fine particles from the second trough, tubes connecting respectively with the second and third troughs, v, barricade through which said tubes extend conveyers extending respectively through the second and third trough and theirres ective tubes, means to rotate. the rolls and rive the conveyers, and means permitting the contents of the second and third tubes transferred thereinto by the conveyers to be discharged beyond the barricade.

In testimony of which invention, l have hereunto set my hand, at Philadelphia, on this 10th day of June, 1912.

FRANCIS I. DU PONT.

Witnesses:

M. M. HAMILTON, E. E. WALL.

Copies of this patent may be obtained for lvev cents each, by addressing the Commissioner of Patents, 'Washington D. 0. 

